words= {'foo':'bar', 'bar':'baz'}
items = words.items()
keys = words.keys()
print(items)
print(keys)
words['span'] = 'egg'
print(items)
print(keys)

a = 'aa'
b = 'aa'

print(id(a), id(b), hash(a))
item = hash(frozenset(set([1,2,3])))
print(item)

set1 = frozenset(set([1,2,3]))
set2 = frozenset(set([1,2,3]))

print(id(set1), id(set2))
